: I had to replace a drippy condensate return pipe in the basement. Since then, my radiators are very noisy. Not banging, but a lot of hissing, enough to wake me up at night. The water level was higher than it should be for some reason (after I replaced the pipe, auto feeder), but I drained some water, and that looks normal now. The drainage was very red. ??? New pipe? Usually it's the typical rust color. Now it's back to the rust color. I'm not sure there's any relation, but I wanted to be complete.: Also, it's a single Input/output system for each radiator, but T's into an upper and lower pipe in the basememt. The top is insulated, the bottom isn't, and the bottom one (I assume the top was steam, the bottom return) was the one that had a few drips and was rusting out, which I replaced.

: thanks for any advice. Also, I have one bedroom radiator that never gets hot. is it just blocked with crud? Can I disassemble and clean it out with something? Or do I need to replace it?

: Rob

Reply:The rust colored water is probably just what got stirred up while you were refilling the boiler after the piping replacement.The hissing noises could have been wet steam that was brought up the the rads when the boiler water level was slightly high.The inoperable rad could have a defective air vent, shut off valve or the piping could have sagged in the floor and is holding water preventing the steam from entering the rad.Rarely does steam piping become blocked with crud.Good Luck. e-plumber